Free llms.txt Checker
Test whether a site publishes an llms.txt for AI crawlers, and whether the file is one they can actually read.
| Verdict | Check | Measured |
|---|
What the llms.txt checker tests
- Present —
/llms.txtanswers HTTP 200 at the site root. - Really markdown — the body is not an HTML page served with a 200 (the common false positive from catch-all routes).
- Opens with an H1 — the convention starts with
# Site nameand a one-line summary. - Links to pages — the number of markdown links; a file with none tells a crawler nothing about which pages to read.
- Content-Type — served as
text/plainortext/markdown. - llms-full.txt — the optional companion file with full page content.
- No file yet? — you get a draft built from your home page's title, description and navigation, ready to edit.
The same facts are collected on every free SEO check, alongside AI-crawler access, structured data and authorship — the readiness signals an AI answer engine can actually use.
A minimal llms.txt
# Example Shop > Handmade ceramics from Lisbon, shipped across Europe. Founded 2015. ## Products - [Dinnerware](https://example.com/dinnerware): plates, bowls and mugs, with prices - [Custom orders](https://example.com/custom): how commissions work ## Company - [About](https://example.com/about): the studio, the makers - [Shipping and returns](https://example.com/shipping)
Questions
What is llms.txt?
A proposed convention (llmstxt.org, 2024): a markdown file at /llms.txt that tells AI systems what a site is and links to the pages worth reading, the way robots.txt tells crawlers where they may go. It is not a standard and no search engine requires it.
Does Google use llms.txt?
No. Google has said no special file or markup is needed for AI Overviews or AI Mode, and it does not read llms.txt. It is read by some AI agents and documentation tools, and it costs nothing to publish — which is why the check reports a missing file as a warning, never a failure.
What does the checker test?
Whether /llms.txt answers 200, whether the body is really markdown rather than an HTML error page served as 200, whether it opens with an H1 naming the site, how many links it carries, the Content-Type header, and whether the optional /llms-full.txt exists.
What should an llms.txt contain?
An H1 with the site name, a one-paragraph summary in a blockquote, then sections of markdown links to the pages that matter most — product pages, documentation, pricing, contact — each with a short description. Keep it under a few hundred lines; llms-full.txt is where full content goes.
Why does mine show “HTML served as 200”?
A catch-all route or a soft-404 page answers every unknown path with the home page or an error page and a 200 status. Add a real file at the web root, or a route that serves text/plain for /llms.txt.
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